Convert the point $(-2,-2)$ in rectangular coordinates to polar coordinates.  Enter your answer in the form $(r,\theta),$ where $r > 0$ and $0 \le \theta < 2 \pi.$
Explanation: We have that $r = \sqrt{(-2)^2 + (-2)^2} = 2 \sqrt{2}.$  Also, if we draw the line connecting the origin and $(-2,2),$ this line makes an angle of $\frac{5 \pi}{4}$ with the positive $x$-axis.

[asy]
unitsize(0.8 cm);

draw((-3.5,0)--(3.5,0));
draw((0,-3.5)--(0,3.5));
draw(arc((0,0),2*sqrt(2),0,225),red,Arrow(6));
draw((0,0)--(-2,-2));

dot((-2,-2), red);
label("$(-2,-2)$", (-2,-2), SE, UnFill);
dot((2*sqrt(2),0), red);
[/asy]

Therefore, the polar coordinates are $\boxed{\left( 2 \sqrt{2}, \frac{5 \pi}{4} \right)}.$